The present invention relates to pressure cookers, more particularly, cookers for the cooking of food or for sterilisation purposes, of the type comprising a pressure receptacle for cooking and a flexible lid suitable for closing the receptacle from the inside, and pressing against a circular seat formed inside the upper edge of the same receptacle.
Pressure cookers currently in use are differentiated one from the other through the closure system adopted. The most widespread are those provided with a “bayonet” closure system, of the type described, for example, in French patent FR 2392639. There, the edges of the lid and of the receptacle for cooking are provided with radial fins, angularly distanced and suitable for engaging and disengaging reciprocally by means of rotating the lid in relation to the receptacle, through a predetermined angle, around the central axis of the cooker. There are also cookers provided with a “jaws” closure system, wherein the lid is provided with a pair of jaws which can move radially from a first position of closure to a second position of opening. In the first position of closure, the pair of jaws bring together and tighten the edges of the receptacle, which are outwardly bending and suitable for the purpose of tightening. In the second position of opening, the jaws move away, disengaging the edges of the receptacle and allowing removal of the lid. In contrast, the Applicant_distinguishes itself in the field of pressure cookers by its closure system with a “lever handle”. In practice, the system is formed by a flexible lid which is inserted inside the pressure receptacle, by a cross member which is positioned outside the edge of the receptacle and by a lever provided at one end with a cam and pivoted above the cross member on a support connected to the lid. Once the lid is inserted in the receptacle, the cross member is rested on the edges of the receptacle and the lever is rotated. During rotation, the cam pushes on the cross member, causing the lid to raise, which abuts against the edge of the receptacle, which is inward bending and suitable for the purpose of opening. The lid is tightened in the close position by ending the rotation of the lever in a horizontal position opposite the starting position.
These systems of opening and closure all represent valid alternative solutions. The relative advantages depends mostly on the comparison between single specific embodiments and the taste and convenience of the purchaser, more than on the inherent features of the type of closure system in an abstract sense. The system with a “lever handle”, which characterises part of the range of pressure cookers of the Applicant, has a series of special features which have gained consensus from part of the consumers, and which in coming years could promote diffusion on new markets. This system, in fact, is absolutely the simplest and the most economical, comprising few components which interact one with the other directly and rationally. Despite the fact that the lid is provided with release valves and with other safety elements present in every type of pressure cooker, it is inserted in the cooker and abuts the recessed edge of the pressure receptacle, totally preventing the possibility of structural breakage caused by removal of the lid from the cooker. This system also does not foresee any preferential positioning of the lid in relation to the receptacle in order to be able to perform the operation of closure. The movement of the lever handle is very intuitive and does not require special effort. However, some people, such as the elderly or those with certain disabilities, could encounter difficulty in opening and closing the pressure cooker. This difficulty may increase if regular maintenance is not carried out and fat vapours, which occur in pressure cookers, deposit in the interstitial areas of the components and harden the movement mechanisms.
The object of the present invention is therefore that of providing a system of opening and closure with a lever servomechanism for a pressure cooker, which maintains all practical and functional features of a pressure cooker at low cost, and which increases the convenience thereof thanks to a gentler and more fluid actuation of the closure lever, such as to make the loading and unloading of the pressure cooker simple and effortless, even for weak individuals.
A further object of the present invention is that of providing a system of opening and closure with a lever servomechanism, suitable for equipping various lines of pressure cookers for a demanding and modern clientele, attentive to the quality of the materials and manufacture, while providing an easy-to-use and low cost system.
The object of the invention is likewise that of providing a system of opening and closure with a lever servomechanism for making pressure cookers safe and reliable due to the fact that the lever abuts the lid on the edge of the container on the inside, thus preventing the lid from blowing off in the event the lever or locking button malfunctions or breaks.
Last but not least, an object of the present invention is that of providing a system of opening and closure with a lever servomechanism wherein the cam of the lever does not press directly on the plane of the cross member placed in a bridge fashion to counter-abut on the edge of the container, so as to allow a considerable reduction in the thickness of this cross member and hence a reduction in the costs associated with the production of the system of closure.